1. Field of the Invention
The present invention relates to an improved electric treadmill, and more particularly to a treadmill with a single motor for adjusting the height of a running board and for folding the treadmill.
2. Description of the Prior Art
The treadmill is an excellent exercise apparatus for the user to make a jogging exercise on the same ground. Simply to speak, it is operated by a main motor to drive a belt which then drives a front and a rear roller unit so that the running belt disposed around the roller unit rotates unceasingly. Therefore, the user can stand on the running belt and make a jogging exercise in accordance with the rotation speed of the running belt.
However, this product is very big and heavy so that it's generally equipped with a lifting and folding apparatus for lifting the running support in order to reduce the occupied space and to facilitate its storage or transportation. In addition, this product is unsuitable for the old and the weak because of its heaviness of the body. Moreover, an apparatus for adjusting the angle of the elevation of the running support is provided to simulate the ground of different slopes.
These two (height-adjusting and folding). units of the prior art treadmill are both manually or electrically operated, or one is manually and the other is electrically operated. No matter how they are operated, they are unpractical in using so that the purchasing and using desire of the user is tremendously reduced. However, the electrically operated type is too expensive that the consumer who desires to purchase it can't afford it.
The reason why the electrically operated type is too expensive lies in that the height-adjusting and folding units have to be fitted with a motor respectively for driving them. In addition, the cost of the material and the assembly for related transmission parts of the motor will also be increased.